Diesel Engines running veg oil - turbo vs. non-turbo?

[Paul the 6th]

Another camper related post (I promise I'll be back asking questions about bikes as soon as I've got a track bike of some kind).. There's a load of guys on the vwt4 & brick-yard forums who are running veg oil as an alternative to diesel. Some are running upto 70% oil to 30% diesel, but most are on around 50/50 depending on the ambient temperature..

Some say that you require a specific bosch fuel pump to deal with the slightly higher viscosity, but it's commonly accepted that the 1.9 and 2.4 non turbo engines will run fine on veg oil. The 1.9tdi and 2.5tdi engine however, are a big no-no.

I read into it, understood it (for the most part) and decided that it's not something I'd like to risk, despite the 30-40p saving per litre. I understand octane and cetane ratings, as well as knocking/detonation, but was just wondering whether the turbo/compression ratio might have something to do with the tdi engines not liking veg oil?

YC & the whacky scientists of the org, enlighten me

[andrewsmith]

Paul PM Carl (Berlin)
He ran a old N/A Iveco lump. The modern common rail diesel cannot run veg oil as the injectors are too small amongst other issues.

[fizzwheel]

Originally Posted by Paul the 6th

but was just wondering whether the turbo/compression ratio might have something to do with the tdi engines not liking veg oil?

When I looked into it, seemed to be two issues

1. Fuel pump not liking it, something to do with the veg oil knackering the seals IIRC, but I might be wrong

2. Common Rail diesel engines dont like veg oil, its not a turbo issue, as said above IIRC its to do with the injector system.

I used to run my 1.9TDI on the bio diesel sold at Morrison's. Never used actual veg oil, so dunno. There was never a concrete answer as to why, though I heard it would eat through the seals and hoses which weren't designed for it, and likewise the injectors and pump would be unhappy.

Injectors clog up with crud when running on veg oil.

[Paul the 6th]

thanks for the replies guys found this post on pistonheads as well which mentions about the amount of back pressure which the pump has to deal with on common rail injection engines..

http://www.pistonheads.com/gassing/t...t=814111&mid=0

ta!

[maviczap]

There's a lot of chat on my Mazda Bongo forum about running on veg oil, and plenty of people do, without any problems.

My Mazda engine is fairly low tech (read tractor like) without any the the common rail gubbins, so it'll happily run on neat rape seed oil.

One guy has run his Mazda for 20,000 miles without any problems and I've seen pictures of another one with a twin tank diesel/ veg oil tank

http://www.youtube.com/watch?v=b5AwH9GdFV4

However there is another type of conversion you can use which is a combination LPG/diesel system. The cost of the conversiopn is only worthwile when you're doing reasonable milage, as you get better MPG

I don't know too much about it, but if you're worried about veg oil buggering up your fuel pump, then this might be an alternative?

http://www.google.co.uk/#hl=en&xhr=t...5367f29cd5c777

[Paul the 6th]

well, I wasn't so bothered about mpg or trying to be more environmentally friendly - purely the £1.40 average cost of diesel compared with around £1.07'ish per litre of SVO..

I'm quite happy with the economy though - 500 miles from 70 litres of diesel for a van is brilliant. Our renault master works van (also 2.5 tdi) holds about 80 litres and gives around 380-420 miles at best!

[husky03]

http://www.vegetableoildiesel.co.uk/forum/

all questions answered here mate-i start producing my own biodiesel this weekend-gonna be costing 70p/litre in total after all production costs-diesel will hit 180 a litre this year me thinks.

[Skip]

My mate ran his 1994 Audi 1.9 TDi on veg oil on and off for about 2 years - then it developed a lumpy idle - turned out to be dirty injectors - now whether the 225,000 miles on them was the cause or the usage of veg oil - who knows! Still going strong though!